Backbone- Routers

In the traditional MVC sense Routers don’t necessarily fit the semantics. Though a Backbone “router” is still very useful for any application/feature that needs URL routing/history capabilities.Backbone routers are used for routing your applications URL’s when using hash tags(#).

Defined routers should always contain at least one route and a function to map the particular route to. In the example below we are going to define a route that is always called.

Optional Routes

Search route with query and optional page parameter is an optional route.

var TodoRouter = new (Backbone.Router.extend({
	routes: {
		'search/:query': 'search',
		'search/:query/p:page': 'search'
	},
	search: function(query, page) {
		page = page || 0;
		console.log(query);
		console.log(page);
	}
}));

Results:

TodoRouter.navigate('search/milk', {trigger: true});

This will print

"milk", 0

TodoRouter.navigate('search/milk/p2', {trigger: true});

This will print

"milk", 2

Note the duplicate routes are highlighted. We can resolve this issue with a optinal route:

var TodoRouter = new (Backbone.Router.extend({
	routes: {
		'search/:query /p:page ': 'search',
	},
	search: function(query, page) {
		page = page || 0;
		console.log(query);
		console.log(page);
	}
}));

What if we want to match ‘search/milk/p2/’?

var TodoRouter = new (Backbone.Router.extend({
	routes: {
		'search/:query (/p:page)(/) ': 'search',
	},
	search: function(query, page) {
		page = page || 0;
		console.log(query);
		console.log(page);
	}
}));

We can use an OPtinla trailing slash

(/)

URI with Spaces

What if the URI you provide has encoded spaces?

To doRouter.navigate('search/Hello%20World/p2', {trigger: true})

You will get the following result, which is not decoded:

"Hello%20World", 2
var TodoRouter = new (Backbone.Router.extend({
	routes: {
		'search/:query (/p:page)(/) ': 'search',
	},
	search: function(query, page) {
		page = page || 0;
		query = decodeURIComponent(query);
		console.log(query);
		console.log(page);
	}
}));

The result will be decoded:

"Hello World", 2

Regex in Routes

Say we want to restrict parameter to numeric input, let’s see how can can achieve this:

var TodoRouter = new (Backbone.Router.extend({
	routes: {
		'todos/:id': 'show'
	},
	show: function(id) {
		console.log("id = " + id);
	}
}));
TodoRouter.navigate('todos/2', {trigger: true})

Result:

id = 2

TodoRouter.navigate('todos/notanid', {trigger: true})

Result

id = notanid

So this shouldn’t trigger show.

var TodoRouter = new (Backbone.Router.extend({
	show: function(id) {
	console.log("id = " + id);
}
}));	

TodoRouter.route(/^todos\/(\d+)$/, 'show');

Here each Regex Capture Group becomes a param.

TodoRouter.navigate('todos/2', {trigger: true}) // id = 2

TodoRouter.navigate(‘todos/notanid’, {trigger: true})

This doesn’t trigger show.

var TodoRouter = new (Backbone.Router.extend({
	initialize: function(){
		this.route(/^todos\/(\d+)$/, 'show');
	},
	show: function(id) {
	console.log("id = " + id);
}
}));	

This keeps routes inside the router.

Advanced Regex Routes

Let’s examine this advanced route formation:

/^search\/(\w+)(?:\/p(\d+))?\/?$/ --> 'search/:query(/p:page)'

This router matches:

'search/milk'
'search/milk/p2'
'search/milk/p2/'

But it doesn’t match the following:

'searches/milk'
'search/milk/p2/p1'
'search/milk/2'

Catch-all Routes

Alert user when no route matches:

var TodoRouter = Backbone.Router.extend({
	routes: {
		'*path': 'notFound'
	},
		notFound: function(path) {
		alert('Sorry! There is no content here.');
	}
});

TodoRouter.navigate('nothinghere', {trigger: true})

This will result in:

File Path Route

Accept a file path and get its parts

var TodoRouter = new (Backbone.Router.extend({
	routes: {
		'file/*path': 'file'
	},
	file: function(path) {
		var parts = path.split("/");
		console.log(parts);
	}
}));

TodoRouter.navigate("file/this/is/a/file.txt", {trigger: true});

Result:

[" this", "is", "a", "file.txt"]

If you want to learn about more follow my other articles on Backbone here:

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